Olive oil

Analyses of phytosterol classes of olive and hazelnut oils collected from different countries by TLC, GC and GC-MS revealed considerable quantitative differences. The composition of 4-desmethyl- and 4-monomethylsterols was similar in both oils, but 4,4'-dimethylsterols composition differed. Lupeol and an unknown (lupane skeleton) compound were exclusively present in hazelnut oil 4,4´-dimethylsterols and could be used as markers to detect virgin olive oil adulteration with hazelnut oil at levels below 4%. Conventional TLC to separate phytosterol classes has a low recovery rate and is time-consuming. A new SPE method to separate phytosterol classes was developed with stepwise elution by increasing the polarity of the n-hexane:diethyl ether solvent mixture. Comparison of the results obtained for hazelnut and virgin olive oils with those of TLC revealed that the SPE method was faster and gave higher sterol recovery rates. Free and esterified forms of sterols provide detailed information on the identity and quality of vegetable oils, and therefore 4,4´-dimethylsterols were investigated in hazelnut oil and virgin olive oil. A sample of solvent-extracted hazelnut oil was refined to monitor the effects of processing on 4,4´-dimethylsterol levels and on specific marker compounds. Of the refining processes tested, only neutralisation and bleaching considerably reduced 4,4´-dimethylsterols. In fully-refined hazelnut oil, losses of marker compounds in free form were higher than losses in their esterified form. GC-MS analysis showed that adulteration of olive oil with fully-refined hazelnut oil could be detected at levels of 2% by tracing lupeol in total/esterified forms of 4,4´-dimethylsterols. Olive oil has many applications in the food industry, e.g. blended with oils such as palm stearin to produce margarine or shortening by chemical interesterification. Investigation on lipid and minor lipid components of an olive oil-palm stearin blend during chemical interesterification showed that sterols were esterified with fatty acids at a higher level at 120 °C (7%) than at 90 °C (4%). Despite heat treatment and several steps to produce an interesterified product, there were minor losses in phytosterol and tocopherol contents and no significant increases in phytosterol oxidation

Amaranth Seed Oil Composition

In this chapter, amaranth seed oil composition will be presented. The main component of this oil is triacylglycerols (TAGs). TAGs are composed of fatty acids, which have an important effect on oil stability, application, and nutritional properties. POL, PLL, POO, OLL, and LOO are the predominant TAGs in the amaranth seed oil. Linoleic acid (C18:2), oleic acid (C18:1), and palmitic acid (C16:0) are the predominant fatty acids present in the amaranth oil. Minor components of this oil are squalene, sterols, tocopherols, carotenoids, phospholipids, etc. Growth conditions of amaranth and extraction conditions can influence oil composition, which will be discussed in this chapter as well. Oil stability and quality parameters will be also discussed. The stability of this oil during different conditions of storage will be a part of this chapter

Plant tonic, a plant-derived bioactive natural product, exhibits antifungal activity against rice blast disease

The tendency towards application of natural products and botanical extracts as safer antimicrobial agents against plant pathogens has recently been increased. Plant Tonic9 (EOX-SOV) is an environmentally friendly product and by its application there is no concern of resistance as it is with conventional pesticides. The goal of the present research was to determine the effect of application of this product against Magnaporthe oryzae, the causal agent of rice blast. The efficacy of plant tonic against M. oryzae was evaluated through in vitro and in vivo experiments. Under in vitro conditions, application of plant tonic at all rates (2, 3, and 4 mL/L) could significantly inhibit the mycelial growth and conidial germination of fungus with the highest inhibition (83.63% and 95.15%, respectively) recorded by the rate of 4 mL. Plant tonic treatment (3 and 4 mL) was more effective than fungicide treatment (propiconazole 25% EC (0.1%); 250 ppm) to inhibit mycelial growth and conidial germination of M. oryzae. Under in vivo conditions, plant tonic application (4 mL) was also the most effective treatment and resulted in a significant reduction (57.12%) of the area under the disease progress curve (AUDPC) value as compared with the control. Application of plant tonic also caused increased accumulation of phenolic compounds and higher activity of peroxidase and polyphenol oxidase enzymes than the control. The maximum amount of phenolic compounds (0.49 mg Gallic acid equivalent/g leaf fresh weight) and the highest activity of the enzymes (1.24 and 7.85 Units/mL for peroxidase and polyphenol oxidase, respectively) were observed in plants treated with plant tonic (4 mL) and challenged with M. oryzae as compared with other treatments. No phytotoxicity was observed in plant tonic treated rice plants when compared with the control. Results of the present study confirmed the beneficial effects of plant tonic in controlling rice blast disease. Therefore, its application may help to develop appropriate management strategies and provide with the opportunity to have cleaner and safer environment for agriculture

Effect of Refined Edible Oils on Neurodegenerative Disorders

Neurodegenerative diseases are comprise a prominent class of neurological diseases. Generally, neurodegenerative diseases cannot be cured, and the available treatments can only regulate the symptoms or delay the disease progression. Among the several factors which could clarify the possible pathogenesis of neurodegenerative diseases, next to aging as the main risk, the dietary related diseases are the most important. Vegetable oils, which are composed of triacyclglycerols as the main components and several other components in a trace amount, are the main part of our diet. This review aims to study the effect of refined or unrefined vegetable oil consumption as a preventive or aiding strategy to slow or halt the progression of neurodegenerative diseases. In the refining process, owing to the chemical materials or severe temperatures of the refining process, removal of the desirable minor components is sometimes unavoidable and thus a worrisome issue affecting physical and neurological health

Some Qualitative and Rheological Properties of Virgin Olive Oil- Apple Vinegar Salad Dressing Stabilized With Xanthan Gum

Purpose: Lipid oxidation and rheological properties are the main qualitative parameters determined in food emulsions. Salad dressings are food emulsions important in our daily diet, but conventional salad dressings have high amounts of cholesterol and saturated fatty acids because of egg yolk in their formulations. There are many studies on the modification of salad dressing formulations to replace egg yolk and saturated fats. The present study describes new formulation of salad dressing with olive oil and apple vinegar to produce a functional food product. Methods: This study investigated the qualitative properties, oxidative stability, rheological behavior and microstructure of the salad dressing without egg yolk. Oil-in-water emulsions were prepared with virgin olive oil and apple vinegar stabilized with various percentages of xanthan (T1: 0.25%, T2: 0.5%. T3: 0.75%). Samples were stored at refrigerator for 90 days and experiments were performed at production day and during storage. Results: The obtained results showed that peroxide value was increased for all samples during storage, but it was at an acceptable level. Fatty acid changes were not significant during storage. Droplet size was reduced by increasing xanthan gum. T2 had the best rheological properties during storage. Generally, T2 and T3 had higher scores and were more acceptable in organoleptic assay. Conclusion: Obtained results showed that T2 had suitable qualitative and rheological properties and can be a proper egg yolk free salad dressing to introduce to the market

Quality of oil extracted by cold press from Nigella sativa seeds incorporated with rosemary extracts and pretreated by microwaves

Black cumin (Nigella sativa) seed (BS) oil has high a peroxide value (PV) and acid value (AV). In this study, BS was incorporated with different levels of rosemary extracts as a natural antioxidant source before and after pretreatment by microwaves. Based on the oil extraction yield (33%), PV (8.4 meq O2 per kg oil), and AV (3.2 mg KOH per gram oil), the optimum condition was determined as microwave radiation for 120 s and, after that, moisturizing by the extract at 4% level. AV and PV were lower, and chlorophylls, carotenoids, polyphenols, thymoquinone, and tocopherols content were higher in oil extracted from pretreated BS than oil extracted from control BS. Reduction and loss of bioactive components occurred in oil samples during the 120 days of storage; however, it was higher in the control sample. There were no significant differences (p < 0.05) in the fatty acid composition of oil samples; however, oxidation and reduction of linoleic acid in the control oil sample were higher (4.2%) than the oil extracted from pretreated BS (2.5%). In conclusion, the oil extracted from the pretreated BS had higher oil extraction yield, high bioactive components, and stability; therefore, microwave radiation and incorporation of rosemary extract before oil extraction from BS is suggested

Effect of co-extraction of pomegranate seed oil with green tea leaves on the extraction yield and quality of extracted oil

Co-extraction of pomegranate seed oil (PSO) with green tea leaves (GTL) (0 [control sample], 2.5, 5, 7.5, and 10% w/w) was conducted by cold-press to evaluate the extracted oil quality during storage. The extraction yield was similar to the control sample up to 5% w/w of GTL. Total phenol and chlorophyll content were increased in the extracted oils with increasing the level of GTL. The acid and peroxide values were increased during the storage and the lowest values were achieved for PSO with 5% GTL. Rancimat analysis also confirmed the PV results, therefore using 5% GTL led to providing the highest induction period (11.5 h). Consequently, using 5% of GTL during the extraction of PSO by cold-press could result in an appropriate extraction yield and also present higher oxidation stability. This method does not need any antioxidant extraction from herbs and is very cost-effective, time-efficient, and uses no chemicals

The Effect of Thermal Sonication of Bioactive Compounds and some of the Quality Parameters of Sour Cherry Juice Compared to the usual Pasteurization Method

The purpose of this study is to investigate the effect of thermal sonication in comparison with the usual pasteurization method on the bioactive compounds and their contents in sour cherry juice.The treatments were: controlled sample, pasteurized sample (90 °C, 30 sec), heated sample at 60 °C for 4,8,12 min, ultrasound sample without heating for same times with amplitudes of 24.4, 42.7, 61µm (50, 75, 100%), ultrasound sample with heating (60 °C) for same times and amplitudes. Pasteurization treatment caused a significant decrease of 31.7% in vitamin C content, 22.9% of phenolic content, 19.4% in the antioxidant content, 6.2% in anthocyanin content of the sour cherry juice. At maximum thermal ultrasound intensity and time of 12 minutes, 20.8% of vitamin C content was decreased. With increasing temperature, intensity and time of ultrasound, phenol content decreased. High intensities of ultrasound caused a significant decrease in anthocyanin content, in a way that in the intensity of 61 µm, 4 min and 60 °C, the anthocyanin content was reduced by 6.6%, respectively. In general, the results of this study indicate that increasing the intensity of ultrasound, temperature and treatment time reduced the positive effect of these treatments on qualitative properties and even reduced the bioactive compounds, that with regard to the combined results, 42.7 µm (75%) amplitude at 60 °C can be the most effective treatment in maintaining the qualitative characteristics of sour cherry juice compared to the pasteurization metho

Characterization of biocomposite films made from carboxymethyl cellulose, okra mucilage, and black cumin seed (Nigella sativa) oil by Response Surface Methodology

The primary aim of this study was to develop biocomposite films using carboxymethyl cellulose (CMC) (1 % w/v), okra mucilage (OM) (1–3 % w/v), and black cumin seed oil (BSO) (0–0.5 % v/v), based on the central composite design. The effects of OM and BSO concentrations on the properties of biocomposite films were evaluated using response surface methodology. Statistical analysis showed that all variables significantly contribute to the model (p < 0.05). The findings indicated that higher BSO concentrations considerably decreased (p < 0.05) the water vapor and oxygen permeability, moisture content, swelling factor, and water solubility of the produced films. Conversely, a rise in OM concentration notably increased (p < 0.05) the physical and barrier properties of the films. It was determined that an increase in OM concentration led to a decrease in tensile strength (TS), while the elongation at break (%EB) increased significantly (p < 0.05). Conversely, higher concentrations of BSO significantly improved both the TS and %EB values (p < 0.05). FE-SEM analysis revealed that for all films, microstructural irregularities increased with higher concentrations of OM and BSO. The formulation containing 1.82 % OM and 0.5 % BSO was identified as an optimal composition. FE-SEM and AFM analyses showed that the optimal film had higher microstructural discontinuity and surface roughness than the control film. The optimal film exhibited significantly higher antioxidant activity (p < 0.05) compared to the control film. Furthermore, FTIR analysis highlighted the presence of new intermolecular interactions within the functional groups of the optimal film’s matrix. Moreover, the optimal film demonstrated a higher melting temperature and a more amorphous structure than the control film. In conclusion, the optimized CMC/OM/BSO film presents promising potential for use in edible packaging

Changes in the quality of oil extracted by hot pressing from black cumin (Nigella sativa) seeds and by solvent from the obtained cake during refining

In this study, oil was extracted from black cumin (Nigella sativa) seed (BCS) by press, and oil was extracted from the obtained cake with a solvent. The changes in the quality of both crude oils obtained by pressing and by solvent were investigated during refining. Findings revealed that the p-anisidin value (p-AV) and fatty acid profile did not change significantly, but there were significant differences (p &lt; .05) in the peroxide value (PV), reflective index, pigment contents, free fatty acid content (FFA%), and antioxidant activity (total phenol content (TPC), thymoquinone, and DPPH inhibition) of BCS oils obtained by the two different methods. PV and FFA decreased to less than 15 meqO2/kg and 0.3%, respectively, in the refined oil. The TPC (65%), thymoquinone (45–97%), carotenoids (86–89%), and chlorophyll (75–85%) were removed from BCS oil, but the DPPH value was raised by about 33%. The current study gives a clear picture of the changes during refining in BCS oil, which can be a useful guide in food applications